Device for recovering LNG (liquefied natural gas) evaporated gas and liquefying again

A device for recovering LNG (liquefied natural gas) evaporated gas and liquefying again includes a storage tank with a safety valve and a low temperature pump, wherein a first interface is arranged between the storage tank and the safety valve, the storage tank is connected with a recovering pipe, and the low temperature pump is provided with a second interface; the other end of the recovering pipe is communicated with a recovering compressor; an outlet is connected with a cooler, an oil and gas separator and an evaporated gas distributor; first and second evaporated gas are shunted, the first evaporated gas is communicated with a screw expander and enters a heat exchanger and a second screw compressor, and the second evaporated gas is connected with the second interface of the low temperature pump after passing through the heat exchanger, a throttle and the oil and gas separator; and then LNG enters the storage tank. The device has the advantages of adopting the screw compressor to directly recover the evapo